There’s a number of things going on here as I understand it. It would have been better if the instructor had dealt with the issue more efficiently. It would have been better if the truck had been repaired properly. I would have been better if the instructor had dealt with the candidate to prepare him prior to his test.
But we all have problems from time to time. I was trained in the industry with the mantra “things mechanical will go wrong”. But now we have the added nightmare of electronics! We have a stringent maintenance regime and still we’re not fault free.
I like to think that we handle such circumstances a bit better than the experience mentioned. In most cases we can provide an identical vehicle for test and we offer a free retest if it goes wrong. Folks understand that things will go wrong from time to time. It’s how it’s dealt with that sets the pro’s apart from the rest.
With a fleet that is only used for driver training, problems will only occur during driver training. And that’s what we live with on an ongoing basis.
It’s a pity the OP walked on test day - but I fully understand it. Personally I would have given it my best shot as passing would have been an extra large feather in the cap. And failing wouldn’t be my fault! But we’re all different and that’s what contributes to the fun and the challenge of the job.
Pete 